Vessel harvesting has traditionally required skin incisions as long as the length of the vessel removed. This technique produces long scars and may result in healing-difficulties. The present invention addresses the need for less invasive removal of vessels. It is adaptable to a wide variety of surgical procedures, including harvesting saphenous vein for peripheral vascular surgery or for coronary artery bypass grafting.
Generally, minimally invasive vessel harvesting with an endoscope is known in the surgical field. In one procedure, a vessel is removed with an endoscope having a lumen therethrough. In this procedure, the saphenous vein is held with a grasper which is introduced through the lumen of the endoscope. After connective tissue has been dissected from around the vein, the vein is then ligated and transected and removed from the lower limb of the patient through the lumen of the endoscope. See, SU 1371689.
Although this method provides for a minimally invasive technique, there are several associated drawbacks. First, in practicing this method there is limited visibility of the saphenous vein and its side branches because viewing is limited to the immediate area directly in front of the endoscope. Secondly, the illumination within the subcutaneous space created by this type of endoscope is also limited to the light emitted directly at the distal portion of the endoscope. Another drawback is that the side branches of the saphenous vein limit the maneuverability of the endoscope since the outer edge of the endoscope body is prevented from advancing along the trunk of the saphenous vein until the encountered side branches are ligated and transected thereby. Perhaps most important, methods which utilize this type of endoscope, i.e. an endoscope having a lumen, provide a working space which is very restricted because the side walls of the scope body confine the working instrumentation to a very limited area. An additional problem is that the lens of the endoscope becomes soiled after touching tissue, so it must be withdrawn and cleaned periodically during vessel dissection and retraction.
Furthermore, the vessel harvesting method described above is typically a three-handed approach which actually requires more than one individual. In this method, one hand is required to hold and maintain the endoscope in position, while a second hand is required to hold the free end of the transected vessel with a grasper and a third hand is required to dissect connective tissue away from the vessel.
Another method for harvesting the saphenous vein is disclosed in "Vein Harvest", Alan B. Lumsden and Felmont F. Eaves, III, in Endoscopic Plastic Surgery (Quality Medical Publishing, Inc., 1995), pp. 535-543. This method provides for performing a preliminary dissection of the saphenous vein while using an open technique prior to inserting an endoscopic retractor such as those commonly used in plastic surgery. In this procedure, once the subcutaneous tissue is retracted with the endo-retractor, a pair of scissors is used to dissect the superior surface of the saphenous vein in order to expose the vein.
A method using both an optical dissector and an optical retractor has been described for endoscopic removal and harvesting of blood vessels. See U.S. Pat. No. 5,667,480. The devices described therein need frequent cleaning of the small endoscopic lens during harvesting, due to the shallow working space beneath the platform and the position of the endoscope within the working head and platform. Also, when multiple instruments, such as a dissector and a retractor, are needed to perform harvesting, they must be inserted beneath the endoscope and outside of the platform passageway. This requires manually lifting the device, which can cause injury to the target vessel and fatigue to the operator. The harvesting devices lack a long semi-tubular hood having side walls that lends numerous advantages to the present invention.
Applicant has devised an apparatus that avoids many of the disadvantages of known methods. Applicant attaches a self-supporting, full-length semi-tubular hood to the shaft containing the endoscope. The hood provides easy access to any subcutaneous site while elevating the downward looking endoscope above and away from tissues so that it is less commonly soiled, thereby avoiding periodic cleaning of the endoscopic lens. Various instruments, such as endo-scissors, endo-staplers, retractors or dissectors, may be easily inserted within the semi-tubular hood during harvesting without withdrawing the entire device.